<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 获取焦点的时候 */
        input:focus {
            color: red;
        }

        /* 表单默认显示的效果 */
        .a {
            width: 100px;
            height: 50px;
            background-color: #f00;
        }

        /* 表单失效时的效果 */
        .a:disabled {
            background-color: rgb(65, 36, 41);
            color: #fff;
        }


        .b {
            width: 40px;
            height: 40px;
        }

        /* 单选或者多选选中的时候的样式 */
        .b:checked {
            width: 50px;
            height: 50px;
        }
    </style>
</head>

<body>
    <input type="text" placeholder="123" disabled>

    <!-- disabled 表单失效 -->
    <input class="a" type="button" value="60s" disabled>



    <input class="b" type="checkbox">
</body>

</html>